Method of and apparatus for forming sheet glass



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www l 4, l as M Filed Feb. 9, 1925 FIG. 2

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I NVENTOR Aug. 14, 1928.

J. E. BLACK METHOD OF AND APPARATUS FOR FORMING SHEET GLASS 2 Sheets-Sheet Filed Feb.2, 1926- FIG. 3

INVENQM/ f 2% llflatented Aug. 14, 1928.

UNITED STATES; PATENT' OFFICE.

.TOTHAM 4l?. BLACK, OF BUTLER. PENNSYLVANIA, rASl(.l TO HARTFORD-EMPIRE COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION F DELAWARE.

METHOD OF AND APPARATUS FOR FORMNG SHEET GLASS.

Application filed February lvlyinvention relates to a method ot and apparatus for toi-nung sheet glassj and is particularly suitable 'for the manufacture of plate glass by a continuous process.

l-lerotofore various attempts have been made to manufacture sheet glass by forming a sheet directly from a bath of molten glass contained in a furnace. One manner in which sheets known as plate glass have been manufaetured consists' in directing a stream ot glass from a turn-ace through a. spout and upon a bottom roll whichfunctions as a taille upon which the glass is iiattened by a sheet-forming roll. The stream 0f glass has been made narrow relative to the width ot the completed sheet so that it has suilicient depth to avoid excessive cooling and YFormation of overlaps or seams during the period required for it to travel from the body 'of molten glass to the forming roll. lt has therefore been thought necessary to direct the stream against the mid portion ot' the forming roll Where it is accumulated to a height suiiioientto cause it to spread laterally along the face of the roll in order that a sheet of the proper Width may be formed.

Contacting of the stream of glass in piled formation against the forming roll, which is usually Water cooled, results in chilling of those particles ot the glass which engage directly against the roll. The lateral spread causes these chilled particles to become mixed with the hotter particles, with the result that reamv is present in the linished sheet. This ream causes such distortion of the lines of vision as to render the sheetunsuitable for the ordinary uses of plat-e glass.

My invention has for one of its objects the provision ot means and a method whereby the stream ot' glass may be so controlled and manipulated as to minimize the formation of reain therein, and contemplates the provision of a. del'leeting member for mann taining the stream of glass out of Contact with the forming roll except at approximately the instant that the glass is ready to enter between the forming roll and the lower roll.

Another object of my invention is to provide means for heating that portion of the stream which ordinarily becomes chilled during the spreading action above referred to.

tine form which my invention may take is shown in the aecompanylug drawing,

22, 19526. Serial No. 85,479.

wherein Fig. l is an elevational sectional lspout 5 it is deposited upon a roll .7 and is carried forward to a sheet-forming roll 7a. The-se rolls are preferably water cooled and are rotated by any suitable means, in the direction indicated by the arrows.v A brush roll 8 for cleaning the roll 7 is also provided. I

The parts thus far described may be of any usual construction.

Beneath the s out 5 I provide a. heating chamber 9 to wiieh fuel may be supplied by burner pipes l0, for the purpose of maintaining the bottomwall of the spout 5 heated, so as to facilitate the How ot' glass. In the older practice above referred to, the glass stream 11 which emerges from the spout is of considerably less Width than the finished sheet l2. This necessitates the accumulation of the glass against the face of a roll similar to the roll4 7a to such depth `that it will spread with sufficient rapidity to maintain the Width of the sheet of glass 12. In order to reduce the depth ot the stream at its forward end and to keep it from piling against the forming roll 7a, l provide a recessed bloclfL 3 3 preferably of refractory material. The bloclt 13 may be suspended in any suitable manner, as by means of ears lll and may be adjusted to- `ward and away from the face of the roll 7, as Well as vertically or transversely ot the stream of glass, as indicated by dotted lines in Figs. 2 and 3. These adjustments may be made in various ways to el'ect proper distribution of the glass as conditions change.

Fuel pipes 15 communicate with the interior of the block 13. 'lhe block is pre erably curved somewhat on. its rear surd tace, as shown in Fig. tl. to facilitate the spread ot' the glass stream. and is maintained at sutliciently high temperature to prevent excessive chilling of those glass particles which come into Contact therewith.

The stream of glass is therefore gradually reduced in depth before it co'mes into contact wit-h the forming roll 7a and pl'cmature chilling by contact with the forming roll is thereby eliminated. since the stream is not engaged by the forming roll until it is only slightly in excess ot the thickness ot the plate to be formed. Furthermore. the glass is in contact with the roll for only a comparatively short period of time. The arrangement also results in a more uniform reduction ot thickneefl ot the sheet when passing along the forming roll.

A skin is formed by the lower` roll 7 upon the underside ot the stream of glass, but the cold particles forming lauch skin do not tend to penetrate between the particles ot the hotter glans, since the skin docs not move relatively to the hot particle. except to Stretch slightly.

I claim as my invention:

1. The method of forming sheet glass, which comprises directingr a relatively narrow stream of molten glass against a heating,r and spreading:r member, and thereafter pass ingr the steam-beneath a forming roll.

2. The method which comprises directing; a stream ot' ,glass between a surface thatr is movable in the direction of flow and a stationary heating surface.

3. Sheet-glass forming apparatus comprising means for delivering a relatively narrow stream of glass. a supportinglr surtace for -said glass, movable in the direction of the line of travel-of the glass, a forming roll. disposed above said surface, a spreading `lock mounted to the rear of the forming roll and at a height to engage the stream and effect spreading,r action thereof, and means for heating,T said block. l

4. Sheet-glass forming apparatus comprising means for delivering a relatively narrow stream of glass, a supporting surface for `Said glass, movable in the direction ot the, line of travel of the glass, a forming roll disposed above said surface, aspreading block mounted to the rear of theV forming roll and at a height to engage the stream and eect spreading action thereof, and meanaonheatmg said spreading block 1nteriorlyaliereot. the said block vbeing` adjustable toward and from the formingl roll in a. direction longitudinally of the stream.

5. Sheet-glass forming apparatus cornprising means for delivering` a relatively narrow stream of glass, a supporting surv face tor said glass, movable in the direction of the line of travel of the glass. a forming roll dispoaed above .Caid surface, and a spreading block mounted to the rear olthe tormin;r roll and at a height to engage the Stream and effect spreading action thereof, the said block beim:1 curved upon ital rear face.

6. Sheet-Haas forming apparatus comv prisincr lucana` for deliveringr a relatively 'narrow stream ot glass, a Supporting sui-tace for said glass. movable in the direction of the line of travel of the glass. a forminj.,r roll diapoeed above Said sui-tace. and a. epreadintr block mounted to the rear of the formingr roll and at a height to engage the stream and effect Spreading action thereof, the lQaid block bein;r curved upon one of its 'glass-engaging faces.

7. Sheet-glass forming apparatus comprising means for delivering a relatively narrow stream of glass, a supporting sur face for said glass. movable in the direction of the line of travel of the glassy, a forming roll disposed above said surface. and a Spreading block mounted to the rear of the forming roll and at a height to engage the eti-cani and effect spreadingr action thereof, the said block having its glass contacting surface. linclined to gradually reduce the thickness of the stream.

I8. Sheebglass forming apparatus. comprisingr means for delivering a relatively thick stream of glass, a Supportintr surface for said :ilass movable in the direction of the line ot travel of the glass, a forming roll disposed above aaid surface, and a spreading block mounted to the rear ol the formingr roll and at a height to engage the etrcam and reduccthe thickness thereof, the said block being 'adjustable toward and from the forming roll, in a direction longitudinally of the stream.

9.-Sheet-glass forming appar-aina, com prising a movable glass-reeeiving Surface, Ameans for directing a relatively thick stream of glass thereto. in the direction of movement of laaid surface, a normally slationary Spreading member mounted in po sition to reduce the thickness of said stream, and means for healing .Caid member.

10. The step in forming A@heet alaaf from a relatively narrow body ot' molten al... which con'ipriees spreading .maid body to the desired width b v a heatingr member.

Signed at Butler, Penna., this .lth day of January, 1926. f

JOTH F. BLACK.

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